How do we know the temperature thousands of years ago?

[SkepticLance]

Swansont said :

 

So where, exactly, am I wrong? You haven't provided a scientifically valid criticism. You have only provided a graph of tree growth measurements. And the temperature calibration wasn't the only limitation I mentioned. I can get (I provided a link before, in the other thread) the temperature data for regions of the US that show that parts of it have cooled over the last 100 years. Does that prove that world hasn't warmed up? So local vs global has to be addressed as well.

 

It's too bad you see this as arrogance. The objection you have presented, scientifically, is crap. That doesn't make the Mann curve right, but I've never argued that point, anyway.

 

Your glacier graph was way too small to read. Doesn't it exist online somewhere else?

 

The twin graphs were provided to show the difference between temperature measurements over 1000 years made with tree rings, compared to the same, but with a switch to direct measurements by thermometer over the last 110 years. As I said, the sole point of this is to show the error that comes from the scientifically untenable practise of changing measurement technique half way through a study and pretending that all the measurements are still comparable.

 

You may not have been defending Mann. That was bascule.

 

Arrogance is not something I am necessarily accusing you of. You must decide for yourself if the description fits. However, the attitude held by some people (unnamed) that their beliefs are unassailable is definitely arrogance. I am not in that category because I have always based my arguments on the doubts and uncertainties and have always pointed out that I could be wrong. So could those who are pro-global warming catastrophisms. Arrogance comes from being in a position where you could be wrong and arguing that you are absolutely right.

 

Sorry about the small size of the glacier graph. I had only a paper copy, from New Scientist 27 August 2005, page 25, which I scanned. It is from a study averaging rate of shrinkage of 169 glaciers from all over the world. Main point is that the rate of glacier shrinkage did not vary much from about 1810 to 1830, through to the late 1990's, when the study ended. I use this to point out that glacier shrinkage does not support the 'hockey stick' of rapid warming after 1910.

[bascule]

However, the attitude held by some people (unnamed) that their beliefs are unassailable is definitely arrogance. I am not in that category because I have always based my arguments on the doubts and uncertainties and have always pointed out that I could be wrong.

 

It's easy to doubt. However you have no real criticisms against the science. You continually attempt to interpret graphs yourself and advance your own completely unevidenced pet theories, all of which contradict basic climate science knowledge.

 

Whenever I ask for a paper to back up any of your claims you have failed to deliver. I've delivered paper after paper to corroborate my claims.

 

You have no science on your side. Just ignorance.

 

Arrogance comes from being in a position where you could be wrong and arguing that you are absolutely right.

 

Perhaps my arrogance comes from being so baffled by your ignorance. I guess you construe my arguments as being "absolutely right" because I'm passionate about defending climate science against fear, uncertainty, and distrust. I certainly admit I and the overwhelming majority of climate scientists could be wrong. That's the nature of science: it's falsifiable. However you're trying to argue that climate science is not trustworthy, and doing so out of ignorance.

 

So, I take it that you have absolutely no criticisms of the GCM input data of any of the 12 reconstructions on the graph I posted? Then why are you still arguing against it?

[SkepticLance]

bascule.

You continually present publications based on theory, calculations, and computer models. These are tools of science but are not examples of strong scientific evidence.

 

I have shown you evidence that this type of work is often highly inaccurate. eg. the USNO models. Yet you persist in giving me anything but empirical evidence and claiming it is strong science. It is not.

 

I should not have to give anyone on this forum lessons in basic science. However, here it is. "The basis of modern science is empirical evidence." Without it, you have superstition.

[bascule]

bascule.

You continually present publications based on theory' date=' calculations, and computer models. These are tools of science but are not examples of strong scientific evidence.[/quote']

 

Theory... based on empirical data.

Calculations... from empirical data.

Models... which use empirical data as input.

 

GCMs have inputs, SkepticLance. I asked you to look up one of the papers from the hockey stick graph, look at what input data they used for their GCM, and come up with a scientific criticism.

 

You can't do this. Why?

 

I have shown you evidence that this type of work is often highly inaccurate. eg. the USNO models.

 

Case instance = often!

 

There are thousands upon thousands of atmospheric models, SkepticLance. There are even more scientific papers published using these models. Pointing out problems with one or two is not indicative of a systemic problem.

 

Yet you persist in giving me anything but empirical evidence and claiming it is strong science. It is not.

 

Theory... based on empirical data.

Calculations... from empirical data.

Models... which use empirical data as input.

 

I should not have to give anyone on this forum lessons in basic science. However' date=' here it is. "The basis of modern science is empirical evidence." Without it, you have superstition.[/quote']

 

Theory... based on empirical data.

Calculations... from empirical data.

Models... which use empirical data as input.

 

If you're going to argue against the validity of the GCM input data' date=' look up a paper, find what inputs they're using, and argue against that.

 

Otherwise, your arguments are completely unfounded.[/quote']

[SkepticLance]

bascule

There are heaps of calculations based on empirical data that have later been shown to be wrong. The Club of Rome 1973 "Limits to Growth" is a classic.

 

Results must be tested empirically.

 

You are right on one point. I have concentrated on one model that is clearly fallaceous, but that was due to the fact that it had been adopted as the basis for a major US Government report. Someone at that time thought it was the BEST model available. If that's the best, what's the rest?

 

The IPCC use a wide range of models, that predict temperature increases from 2C to 6C approximately. If that's not doubt and uncertainty, then what is? Other climate scientists have come up with models that predict over 12C increase in 100 years.

 

And you would like to claim this is some kind of exact science?????

[swansont]

Swansont said :

 

So where' date=' exactly, am I wrong? You haven't provided a scientifically valid criticism. You have only provided a graph of tree growth measurements. And the temperature calibration wasn't the only limitation I mentioned. I can get (I provided a link before, in the other thread) the temperature data for regions of the US that show that parts of it have cooled over the last 100 years. Does that prove that world hasn't warmed up? So local vs global has to be addressed as well.

[/i']

 

The twin graphs were provided to show the difference between temperature measurements over 1000 years made with tree rings, compared to the same, but with a switch to direct measurements by thermometer over the last 110 years. As I said, the sole point of this is to show the error that comes from the scientifically untenable practise of changing measurement technique half way through a study and pretending that all the measurements are still comparable.

 

 

But you haven't done that, and changing measurement techniques is only untenable if there is a bias between them. You say that the measurements are "pretending" to be comparable; did Mann calibrate the measurements or not? I don't see a discontinuity in the data, which is one thing you might expect if the two techniques were not comparable. And you still haven't addressed the issue of the geographical area of the data. If you are using a local measurement to compare to a global one, it means nothing. You can have local behavior that is different than the global. This applies to the glacier data as well.

[SkepticLance]

Both studies claim to be global. Of course, both of us are likely to take that with a pinch of salt. A major source of error in all such studies is likely to be the limited number of samples.

 

Neither of us is likely to convince the other on the basis of this kind of study. I do not claim anything to be 'proof.' You and I both know that 'proof' in science is a chimera. It does not exist. What I have provided is evidence. You may decide it is insufficiently convincing. That is your prerogative.

 

However, I go back as always to my original statement. We cannot predict the future of the world's climate. Computer models are widely variable and likely to be wrong. Studies like Manns are similarly fallible and likely to mislead. I do not claim to be right. Just someone who points out the doubts and uncertainties that exist in this field.